Urinary tract infections

Urinary tract infections (UTIs) are a relatively common condition in dogs, especially in females. They can occur as isolated infections or they can be recurrent, particularly if a dog has underlying health conditions. Recognizing symptoms early is an important step toward making a diagnosis and starting treatment. 


UTIs generally occur when bacteria enter the bladder from the external environment, evade the body's immune defenses and cause infection. E. coli is the most common bacteria identified in UTIs.  

While UTIs often refer to infection in the bladder (bacterial cystitis), infection could occur anywhere in the urinary tract from the urethra to the kidneys (where it becomes a condition known as pyelonephritis). Recurrent infections are defined as at least two infections in six months, or at least three in a year. 

Clinical signs 

The most common signs of a UTI include: 

  • Straining to urinate 

  • Frequent, small amounts of urination 

  • Accidents in house 

  • Foul smelling urine 

  • Excessively licking genitals 

  • Blood in urine 

Risk factors 

Certain underlying medical conditions can make dogs more susceptible to UTIs. These include: 

  • Bladder stones 

  • Urinary or fecal incontinence 

  • Diabetes  

  • Cushing’s disease 

  • Intervertebral disc disease  

  • Anatomic abnormalities (ex. hooded vulva, ectopic ureters) 

  • Immunosuppressive medications  

  • Kidney disease 

  • Cancer 


If a UTI is suspected, a test called a urinalysis should be performed to look for signs of infection, including white blood cells, bacteria and red blood cells.  

The urine sample is commonly obtained by a cystocentesis — a simple procedure in which a needle is inserted into the bladder, collecting urine in a syringe and limiting contamination from external sources. A urine culture and sensitivity test are often performed after a urinalysis in order to confirm an infection, determine the exact type of bacteria infecting the bladder and the most effective antibiotics for treatment.  

Depending on the health of your dog, your veterinarian may want to perform additional tests. This may include blood work, ultrasounds, X-rays and other forms of imaging.  


UTIs are treated with antibiotics. Initially, an antibiotic may be prescribed that targets the most likely bacteria causing infection. After the culture finalizes (which may take a few days), your veterinarian may need to change the antibiotic if the results indicate the first antibiotic is not ideal.  

Pain medication is often prescribed to relieve discomfort associated with the infection. For infections that have underlying causes, treatment will also involve management of those conditions. 

Bacteria is sometimes seen on a routine urinalysis; however, this does not necessarily mean an infection is present. Only dogs with signs and symptoms of a UTI should be treated — this avoids accidental overuse of antibiotics, which can lead to more resistant and hard to treat bacterial strains.  


Most bladder infections should resolve relatively quickly with a course of antibiotics. If signs do not completely resolve, your dog should be rechecked by your veterinarian.  

The outcome for recurrent bladder infections will depend on susceptibility to antibiotics and management of underlying causes. 


Many UTIs that occur are unavoidable. Those that are associated with risk factors can be mitigated by proper identification and management of those underlying causes.